This study investigates the prospects for consolidating a promising research agenda: the “crime-geopolitics nexus” – here conceptualized as an eclectic space for producing scientific studies concerned with the interstice between international relations, organized crime, and geopolitics. It provides insights into the geopolitical rationale in which criminal non-state actors operate in the international context to define their strategies, promote their transnationalization, formulate alliances, and improve their control over the management of relevant territories, illicit markets, and institutions along illicit supply chains. Based on a four-chapter division, this research answers the following question: what is the geopolitical role of the Amazon Forest in illicit environmental supply chains? The first chapter presents the study’s theoretical and methodological foundations. The second chapter promotes a dialogue between International Relations, Criminology, and Geography to evaluate the existing approaches toward crime and geopolitics. It also introduces its approach to dealing with the crime-geopolitics nexus. The third chapter focuses on relevant aspects of transnational environmental crimes. The final chapter examines the strategic hubs for transnational environmental crimes located in the Amazon Forest and the networked dynamics of illicit supply chains, from the local to the global level. It concludes that the Amazon Forest plays a significant geopolitical role in transnational environmental crimes globally.